This invention relates to a load transporting apparatus. Such apparatus are used to push or pull heavy loads over a ground surface and typically include ground engaging wheels which are driven by a motor to effect said movement. In order to ensure efficient drive, it is desirable to transmit some of the weight of the load to be moved on to the ground engaging wheels, to ensure a good grip with the ground surface during movement.
One prior art such apparatus includes a three wheels which are supported for rotation relative to a main body. One of the wheels, which is positioned generally centrally of the main body and towards a front end thereof, is driven to rotate about a fixed axis by a motor which is supported by the main body. The remaining two wheels are a pair of castor wheel assemblies which are positioned one generally towards each side of the main body and at an opposite, rear, end of the main body. The three wheels therefore provide a tripod of wheels which support the main body as it transports a load. The apparatus includes a handle/control which serves to provide a user graspable handle to control the direction in which the apparatus moves. The handle includes controls for controlling the speed of rotation of the front wheel.
In order to provide a connection to the load to be transported, the front end of the main body is provided with a lifting device, having a coupling which is moveable in a generally vertical plane and is adapted to engage and bear the load to be transported. Such a lifting device may be manually moveable in the vertical plane, but may be moveable by means of an appropriate drive mechanism, e.g. a hydraulic piston/cylinder arrangement.
One problem with such devices is that when they are engaged with a load to be moved, especially a heavy load, one or both of the rear castor wheels are lifted from engagement with the floor surface. This can provide the user with difficulties in manoeuvring the apparatus, and thus the load. In addition, the rear castor wheel(s) being displaced from the floor surface can give rise to safety concerns, as it is possible for a user's foot to be positioned beneath the wheel, which could then become trapped if the lilting device fail or the coupling to the load failed.
It is an object of the present invention to address these issues.
According to a first aspect of the invention we provide a load transporting apparatus including:                a main body;        a ground engaging wheel positioned at or towards one end of the main body and supported for rotation about a generally horizontal axis;        a support member, which is connected to the main body, and which supports a pair of wheel assemblies, each assembly including a wheel which is supported for rotation about a generally horizontal wheel axis, wherein said wheel assembly permits the wheel to swivel about a swivel axis which is substantially perpendicular to the wheel axis and off-set therefrom;        wherein the support member is connected to the main body by connection means which permits movement of the main body towards and away from the support member.        
According to a second aspect of the invention we provide a load transporting apparatus including:                a main body;        a ground engaging wheel positioned at or towards one end of the main body and supported for rotation about a generally horizontal axis;        a support member, which is connected to the main body, and which supports a pair of wheel assemblies, each assembly including a wheel which is supported for rotation about a generally horizontal wheel axis, wherein said wheel assembly permits the wheel to swivel about a swivel axis which is substantially perpendicular to the wheel axis and off-set therefrom;        wherein the support member is connected to the main body by connection means which is configured to permit rotation of the support member relative to the main body about an axis which extends generally in a fore-aft direction of the apparatus.        
Thus, in the second aspect of the invention the or a further connection means is configured to permit rotation of the support member relative to the main body about an axis which extends generally in a fore-aft direction of the apparatus.
Further features of the first and second aspects of the invention are set out in the claims appended hereto.
According to a third aspect of the invention we provide an apparatus according to the first aspect of the invention including any one of the features of the second aspect of the invention.
According to a fourth aspect of the invention we provide an apparatus according to the second aspect of the invention including any one of the features of the first aspect of the invention.